1. Field of the Invention
The present invention relates generally to electronic component packaging. More particularly, the present invention relates to a method of fabricating a microelectromechanical device package.
2. Description of Related Art
Microportable projectors were capable of projecting digital images with remarkable clarity and color. The cornerstone of these microportable projectors was the micromirror device chip.
As is well known, a micromirror device chip included a micromirror device area, which selectively reflected visible light to project the digital images. More particularly, the micromirror device area contained an array of miniature moveable micromirrors, sometimes called microscopic mirrors. These microscopic mirrors were selectively switched on and off, which in turn selectively reflected the visible light to form the digital images.
However, these microscopic mirrors were extremely sensitive to moisture and contamination. For this reason, the micromirror device chip was hermetically sealed in a seam welded housing. This housing supported a window above the micromirror device area. However, providing and seam welding such a housing was extremely expensive and thus significantly added to the fabrication cost of the microportable projector.
Further, it was important that the microportable projector be as small and light as possible. However, the housing, which hermetically sealed the micromirror device chip, was relatively bulky and heavy.
In accordance with the present invention, a window is mounted directly to an upper surface of a micromirror device chip. More particularly, the window is mounted above a micromirror device area on the upper surface of the micromirror device chip by a bead. The window in combination with the bead forms a hermetic enclosure about the micromirror device area thus protecting the micromirror device area from moisture and contamination.
Advantageously, the resulting micromirror device package is fabricated at a relatively low cost, is relatively thin and lightweight, and can readily be used to fabricate a variety of micromirror device assemblies.